Process of recovering barite from its native materials



March 27, 1951 w. c. WOLF 2,546,247

PROCESS OF RECOVERING BARITE FROM ITS NATIVE MATERIALS Filed Dec. 17, 1947 INVENTOR WILLIAM C. WLF

ATTORNEYS.

Patented Mar. 27, 1951 UNITED STATES PATENT OFFICE PROCESS OF'REOOVERING BARITE FROM ITS NATIVE MATERIALS 'WilliamU. Wolf, Potosi, M0. .Applicationilecember-l'l, 1947, Serial No. 792,139

21Claims. l

Thisinvention relates generally-to the recovery of barite from native minerals and-particularly to a process and apparatus-for-separatingbarite from the material with which it is ,found in nature.

Heretofore, in the mining,.,of barite or tififi I asrit -is-colloquiallycalled, it .has been the practiee to truck or tram large quantitiesof clay, sand, and rock .(such as .fiint, sandstone or limestone), with such barite assmaybe present in nature, from the diggins to themill site whereat the bariteis, by series of operations, ,recovered from the native materials. It .iscommon practice that the milling be: done several miles from the'point at which the mining operation took place and consequently a great :array of transportation equipment has beeh necessary.

In the usual procedure pf recovering barite from the native materials ,at the mill, the large rocks are separated .by hand from .a t given batch of barite, clay, sand, rock,,-etc.,..and any large pieces of barite are broken, generally by hand sledge, in order to reduce themixture of dirt, gravel, sand, .and bariteto a fineness-suitable for being handled bythe-familiar log washer. In the latter apparatus; the barite issepara'zed from the other materials,-

The objectof the :present-inventiongenerally stated is to improveandexpediterecoveryof barite .from its native materials.

A particular-object of the presentainvention is. to provide a.processsuitablev for reducing:

barite, whilemixed with native .materials, 1701 8 pumpable fineness without reducing. any. substantial part of the native-rock'to suchrpumpable;

fineness;

Other objects will become apparent to those skilled in therart when the =following description is read in connectionuwithrtheraccompanying drawings in which:

Figure 1 is a view inside ,elevationofan apparatus constructedrin accordancewiththe present invention-for thetreatment of barite with native dirt and rock and .for reducing the .same to :a pumpablefineness;

Figure 2. isia sectional lview taken .along. line 2-2-0f Figured; and

Figure .3 is a diagrammaticvieweshowing: the

disposition of the apparatusof Figures =1 and 2.

inconnection with otherappa-ratus for the ,processingof barite.

According to the presentinvention generally stated, the-:run of mineobarite ore (including clay, sand, barite'and otherrock) -is-deposited inv an apparatus :capable ofreducing the bariteto a pumpablefineness of for example three-' quarters of an. inch without, :however, reducingany substantial' proportion-of the other rock" present .tosuch ,pumpable1fineness, The appa ratus :not only selectively reduces the particle:

til)

terfraotion of the raw ore is incorporated with copious quantities of water so as to'constitute a slurry capable of being conducted throughpipe lines. Where thesolids in the slurry are all of size such as to pass a screen, the product maybe treated in the usual log washer and jigs without further reduction.

Given a generous water supply at the mining site, the above mentioned breaking and separation apparatus is preferably located insuch proximity to the ore pits that' the ore may betreated immediately as it is taken from'the earth. The resulant slurry may then be. pumpedto aremotely situatedmill. If desired, the breaking and separation apparatus may be semi-portable so as to follow-the progress of digging with appropriate extension of the slurry-pipe lines; If desired, the breaker may be elevated so that the slurry may vflow-bygravityto a nearby log washer thus eliminating the necessity for a pump between the breaker and the log washer.

Referring now to the drawings for-an illustrativeembodiment of the invention, a drum l is mounted 'for rotation about a substantially horizontal axis. The drum! is-of diameter such that a pieceofbarite falling from the top to the bottom thereof gains suflicient kinetic energy that upon impact at the bottom of thedrum the-same will fracture; Barite is relatively brittle and of very 'high'specific gravity, being on theorder of 4 .5. The other native-rockis not only, as arule,

considerably harder than barite, but invariably of 'acspecific gravity on the order-of about half that-of barite. Consequently, the idea diameter for the'drum is such that while apiece of barite (larger than pumpable size) dropped across the diameterthereof will fracture, a piece of native rock (of the'same size) dropped the same distance will not fracture. Consequently, by repeating the dropping of the mixture of barite and native rock across such diameter, the barite particle size is reduced, whie that of the native rock is not reduced in any substantial measure. In the latter'connection, itmay'be pointed out that, whilerelatively large pieces of native rock may-fracture and be reduced from a size of, say, a foot in diameter tOSiZGSiOf four or five inches, and some fines will, of course, result from such reduction of the rock, the reduction of'the particlesizeof the barite nonetheless continues below the 'four'to five inch size and down to minus threequarter inches. or even less.

Inthe embodiment shown, the drum I is wfabricated of eight peripheral plates-2 so that the drum is octagonal in crosssection, asshown in Figure 2;

At the junction between the respective plates 2, ribs 3 extend radially inward for a substantial distance. The ribs 3 are preferably vented, as shown at 4, but the vents in adjacent ribs are preferably staggered in the axial direction.

Opposite each of the ribs 3 and extending radially outward from the plates 2 is a bucket 5. The radial walls of buckets may be cut out to reduce the quantity of slurry carried up by them. The ribs 3 and the buckets 5 extend for the full length of the drum I on the interior and exterior thereof, respectively. In the embodiment shown, the drum I has a diameter on the order of seven feet. The ribs 3 extend interiorly of the drum Walls for a distance on the order of six inches and the buckets 5 extend radially outward for a distance of six inches. The dimensions just given will be found advantageous for the treatment of barite ore as mined in Washington County, Missouri, but it will be understood that the conditions peculiar to barite ores from other localities may dictate some change in the dimensions just indicated.

Arranged below the drum I and embracing the lower segment thereof is a tank 6 provided with a weir 1 extending upwardly for a distance suflicient to control the water level in tank 5 so that the internal ribs 3 when in their lowermost position will be immersed, save for the upper extremities thereof. If desired, the tank 6 may be provided with a false bottom 8 built on a radius slightly greater than the maximum radius of the buckets 5. In practice, however, the material being treated will settle in tank 6 and form its own bottom having the contour generally indicated for false bottom 8. Consequently, whether the false bottom 8 is incorporated as a piece of the apparatus or not will depend upon the economies of each particular operation.

The drum I is provided with end plates 9 and I0, each of which has a central aperture. Through the central aperture in the plate 9 a chute I I extends from a hopper I2 so as to admit the raw ore (clay, sand, barite, and rock) into the apparatus. The central aperture in end plate I0 may be provided with a skirt It for guiding the rock which discharges from apparatus through the central aperture in end plate It.

The drum I may be mounted for rotation about a horizontal or substantially horizontal axis in any suitable way. In the form shown in the drawings, each of the end plates 9 and II] is provided with a guide ring It mounted in suitable trunnions I5, which latter may be supported on any suitable framework preferably on the exterior tank 6. One of the guide rings is provided with a ring gear I6 arranged to be driven by a motor I'I so as to rotate the drum about a substantially horizontal axis at the desired speed which is preferably on the order of six revolutions per minute.

During the treatment of the raw material in the drum I copious quantities of water are introduced. Part of the water is preferably introduced through a pipe I8 having outlets within hopper I2 so that as the raw material descends chute I I it is very wet. For example, if the raw material is fed to hopper I2 at the rate of one cubic yard per minute, as much as 100 to 200 gallons of water per minute may be introduced through the pipe I8. At the discharge end of the drum I another pipe I9 having a spray head 28 is provided for continuous spraying of the material undergoing treatment within drum I. More water per unit of material treated is preferably introduced through pipe I9 than through pipe I8. In the case of the treatment at the rate of one cubic yard of raw material per minute as much as 200 or 300 gallons of water per minute is preferably introduced through pipe I9.

Each of the plates 2 is perforated with a great multiplicity of apertures 2|. In the embodiment illustrated the apertures 2| are flared toward the outside and have an inside diameter of approximately three-quarters of an inch which is to say that the apertures 2| will pass material of a minus-three-quarters size.

The arrangement of the tank 6 beneath the drum I is such that the tank catches all of the material, water, and solids which pass through the apertures 2|. The tank 6 extends at one side (the left as seen in Figure 2) beyond the drum I so that solid material (barite, gravel, clay, or sand) which has passed apertures 2| and deposited itself in one of the buckets 5 will be dropped from the bucket when during rotation of the drum, the bucket reaches the upper left quadrant (as seen in Figure 2). The solid material thus dropped from the bucket 5 will be caught by that portion 22 of the tank, which is located on the left of weir I.

From section 22 of tank 6 a discharge line 23 extends to a centrifugal pump 24, the operation of which is adjusted to withdraw the slurry from tank 6 at a rate such that the level in section 22 of tank 6 is maintained substantially below the level to the right of weir I.

By maintaining the fluid level in tank 6 so as to substantially immerse the ribs 3 the perforations 2| in the plates 2 are efliciently kept clear. It is only during the period during which a given aperture 2| is immersed that material will travel in any substantial degree from the interior to the exterior of the drum I. Since during this time the aperture 2| which is being traversed is immersed in fluid there is little tendency for the aperture to become clogged and such tendency as exists is effectively relieved by the movement of that aperture in the 5 oclock position (as seen in Figure 2) where a counterflow from the exterior to the interior is induced. Moreover, as the buckets 5 rise out of the bath contained in tank 6 they are laden with slurry. Continued ascent of the buckets permits the slurry to drain back to the interior of the drum thus dislodging any particles which may have become seated in the apertures 2|.

From the pump 24 the slurry consisting of, for example, 1.5 parts by volume of water to each part of solids (clay, sand and minus threequarters barite, together with any gravel of minus three-quarters size) is conveyed through a pipe line 25 to a separating apparatus such as a log washer 28 which may be situated at a remote point. The pipe line 25 is of a size such that the flow of slurry through the same is at a relatively rapid rate. For example, where the pipe line is required to discharge 500 gallons of water together with one cubic yard of solids per minute, a six inch pipe line is preferable. In such a sitnation, the velocity of the slurry stream through pipe line 25 is sufficient to transport the heavy particles of barite without loss by settling. The viscosity of the slurry, due to the presence of the clay, facilitates the transportation of the barite through the pipe line and to some extent reduces the tendency of the latter to settle, but it should be pointed out that when operation of the apparatus is interrupted it is desirable to continue the injection of water through pipes l8 and I9 and continue the operation of pump 24 for some minutes in order to assure that the pipe line 25 is cleared. If, on the contrary, the slurry were permitted to become static in pipe 25, settling would occur to an extent which might result in clogging the pipe line.

In the operation of the apparatus, the charge from chute I l is deposited in the bottom of drum I, but as the latter rotates the charge is elevated by ribs 3 until in the upper right quadrant (as seen in Figure 2) the ribs are tilted inwardly so that the mass is released from its shelf. Thereupon, the material cascades toward the bottom of the drum. During such fall large pieces of barite gain sufiicient kinetic energy to equal the work of fracturing them. Consequently, when a given piece of barite (of plus three-quarter inch) falls and strikes the free edge of a blade 3 the same will fracture whereas a piece of flint of the same size would not fracture. This is not only because of the greater impact strength of the flint but also because of the barites greater mass per unit of volume, and follows from the physical law that kinetic energy of a freely falling body= Mv From the foregoing description those skilled in the art should readily understand that the invention accomplishes its objects and provides an apparatus which not only eliminates the undesirable rock from the ore but concurrently reduces the barite to a pumpable fineness and at the same time incorporates the same into a slurry of clay and water, so as to enable transportation through pipe lines to a gravity separating apparatus situated at a remote point.

While the invention has been described with particular reference to the recovery of barite from native materials, it should be understood that the invention is not limited to the treatment of barite ores. On the contrary, the invention is applicable to the treatment of any ore wherein the value is of a specific gravity much higher than that of the other native materials and where the value as well as the native rock may come in large pieces. While one complete embodiment of the invention has been disclosed in detail, it is to be understood that the invention is not limited precisely thereto nor to the dimensions which were given hereinbefore for the purpose of illustration. Those skilled in the art will readily understand that the apparatus disclosed is subject to many and varied modifications without departing from the spirit of the invention, and consequently it is to be understood that the invention is not limited to the embodiment described or otherwise, save as indicated in the appended claims.

Having thus described the invention, what is claimed is: l

1. In the recovery of barite from unsized native materials composed of lumps of barite and lighter rock over a predetermined size together with fine material under the predetermined size, the process of selectively comminuting the oversize barite particles and separating the over-size lumps of lighter rock which comprises, providing a screen sized to pass material under the predetermined size, submerging part of said screen in a body of liquid, charging the unsized material into the body of liquid above the submerged part of said screen, repeatedly elevating the unsized material from and dropping the same 'nto the body of liquid above the submerged part of said screen from an elevation which provides a free fall for a distance such that the kinetic energy gained by freely falling lumps just larger than said predetermined size is sufiicient to fracture such lumps of barite upon impact with a rigid body adjacent the surface of said body of liquid but insufficient to fracture such lumps of lighter rock, and continuously passing the under-size material through the submerged part of said screen.

2. The process of claim 1 wherein the liquid is periodically fiowed through said screen in the direction opposite that in which the under-size material is passed.

WILLIAM C. WOLF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 143,745 Bradford Oct. 21, 1873 154,733 Warren Sept. 1, 1874 292,075 Vanduzen Jan. 15, 1884 402,845 Loughran May 7, 1889 471,322 Wyman Mar. 22, 1892 647,336 Sulman Apr. 10, 1900 1,002,182 Ruhm Aug. 29, 1911 1,239,286 Marcy Sept. 4, 1917 1,247,526 Guettler Nov. 20, 1917 1,570,897 Knoblauch Jan. 26, 1926 1,684,366 Dolbear Sept. 11, 1928 1,798,459 Elmore Mar. 31, 1931 2,031,697 Fahrenwald Feb. 25, 1936 2,105,597 Hoyt Jan. 18, 1938 2,199,729 Peterson May 7, 1940 2,282,887 Roberts May 12, 1942 2,286,132 Walle June 9, 1942 2,335,050 Borton Aug. 8, 1944 2,456,266 Gates Dec. 14, 1948 FOREIGN PATENTS Number Country Date 590,389 France Mar. 18, 1925 110,647 Austria Sept. 25, 1928 OTHER REFERENCES Bureau of Mines RI 3564, pages 15 to 22, So. Lib. TN1U8, May 1941. 

